Noninvasive protection from emboli

ABSTRACT

A system for diverting emboli within a patient can include a device that detects a presence of emboli in a first blood vessel of a patient. A compression member can be aligned with a second blood vessel of the patient when a collar supporting the compression member is positioned at least partially around a portion of the patient. In response to the detection device, a controller can actuate the compression member, when the presence of emboli is detected, from an unactuated state to an actuated state in which at least a portion of the compression member (i) is closer to the second blood vessel than while in the unactuated state and (ii) compresses and limits blood flow through the second blood vessel.

RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent ApplicationNo. 61/988,217, filed May 4, 2014, titled NON-INVASIVE METHOD OFPROTECTION FROM EMBOLI, the entire contents of which are incorporatedherein by reference.

FIELD

The subject technology relates to prevention of embolic and ischemicinjury (such as ischemia and stroke) as a consequence of emboligenicevent and interventions.

BACKGROUND

Arterial embolism, leading to embolic ischemia or stroke, is one of themost dreadful complications of cardiac, aortic and vascular procedures,diagnosed in 1-22% of patients undergoing cardiovascular surgery. Evenmore frequently, in up to 70% of cases, patients undergoing heart,valve, coronary artery bypass or aortic surgery experience subclinicalembolic events. These embolic events lead to cognitive impairment anddisability, extremity ischemia and multiple organ failure, having asignificant impact on patients' recovery.

The main sources of emboli in this setting reside in the heart, heartvalves, thoracic aorta, and great vessels when these structures areintervened thereon (i.e. when an emboligenic procedure is performed).Even simple cardiac catheterization with an endovascular catheter caninduce microtrauma of the atherosclerotic thoracic aorta leading toformation of embolic particles with subsequent embolic brain, liver,kidney and extremity injury ranging from latent ischemic foci to amassive or even fatal event. Multiple devices are known that attempt toprevent embolization of the carotid arteries during endovascular andcardiac interventions by using different types of filters, deflectiondevices or endoluminal balloons. These anti-embolic devices, however,have not received wide acceptance in surgery of the heart, heart valvesand thoracic aorta due to their complexity and invasive character withthe risk of additional trauma to the inner vessel wall resulting in ahigh risk to benefit ratio. Known devices require insertion ofadditional hardware into the arterial system or aorta, a procedure thatis known by itself to be associated with all classical risks ofendovascular intervention, including aortic dissection, bleeding,thrombosis, and arterial embolization. One known intra-aortic filterdevice that is inserted into the ascending portion of the thoracic aortavia an aortic cannula to capture potential embolic material releasedfrom the heart and aortic wall during heart surgery was found to bequite difficult to implement and was reported to be associated withmajor trauma to aortic wall and acute aortic dissection.

Aside from introducing hardware into the patient and causing theaforementioned problems, intravascular filters are not able to captureembolus smaller than the pore size of the available devices (currently60-140 μm) resulting in cerebral microembolization. Furthermore, theplacement of the filter by itself may produce cerebral emboli. Forexample, the mere passing of a guide wire into a carotid arterygenerates approximately 40,000 microemboli, with a significantpercentage of small, less than 60 μm, particles that are not retained bystandard filters. Therefore, in spite of multiple innovations in thefield of anti-embolic devices, the problem of arterial emboli and strokeduring cardiovascular surgery is far from being resolved. As such, thereremains room for variation and improvement within the art.

SUMMARY

The subject technology is illustrated, for example, according to variousaspects described below. Various examples of aspects of the subjecttechnology are described as numbered clauses (1, 2, 3, etc.) forconvenience. These are provided as examples and do not limit the subjecttechnology. It is noted that any of the dependent clauses may becombined in any combination, and placed into a respective independentclause, e.g., clause 1, 6, 14, or 21. The other clauses can be presentedin a similar manner.

-   -   Clause 1. A system for diverting emboli within a patient,        comprising:        -   a detection device configured to detect a presence of emboli            in a first blood vessel of a patient;        -   a compression member configured to be aligned with a second            blood vessel of the patient when a collar supporting the            compression member is positioned at least partially around a            portion of the patient;        -   a controller configured to actuate the compression member,            when the presence of emboli is detected, from an unactuated            state to an actuated state in which at least a portion of            the compression member (i) is closer to the second blood            vessel than while in the unactuated state and (ii)            compresses and limits blood flow through the second blood            vessel.    -   Clause 2. The system of clause 1, wherein the second blood        vessel is downstream of the first blood vessel.    -   Clause 3. The system of clause 1, wherein the detection device        blood vessel is configured to detect a threshold amount of        emboli in the first blood vessel, wherein the controller is        configured to actuate the compression member when the detected        emboli exceeds the threshold amount.    -   Clause 4. The system of clause 1, wherein the detection device        comprises a Doppler ultrasound device, a Doppler probe device,        an oscillotonometry device, an electroencephalography device, a        transcranial Doppler device, a pulse indicator device, a cardiac        Echo device, a pulse oximeter, or a cerebral oximeter.    -   Clause 5. The system of clause 1, further comprising a        supplemental detection device configured to detect a presence of        emboli in a third blood vessel of a patient, upstream of the        second blood vessel.    -   Clause 6. A method for diverting emboli within a patient,        comprising:        -   detecting a presence of emboli in a first vascular location            of a patient;        -   when the presence of emboli is detected, actuating a            compression member aligned with a second vascular location            of the patient when a collar supporting the compression            member is positioned at least partially around a portion of            the patient, from an unactuated state to an actuated state            in which at least a portion of the compression member (i) is            closer to the second vascular location than while in the            unactuated state and (ii) compresses and limits blood flow            through the second vascular location.    -   Clause 7. The method of clause 6, wherein the second vascular        location is downstream of the first vascular location.    -   Clause 8. The method of clause 6, further comprising:        -   determining whether the detected emboli exceeds a threshold            amount;        -   wherein the compression member is actuated when the detected            emboli exceeds the threshold amount.    -   Clause 9. The method of clause 6, further comprising:        -   determining whether the detected emboli does not exceed a            threshold amount;        -   transitioning the compression member to the unactuated state            when the detected emboli does not exceed the threshold            amount.    -   Clause 10. The method of clause 6, further comprising        transitioning the compression member to the unactuated state        after the compression member has been actuated for a        predetermined time limit.    -   Clause 11. The method of clause 6, wherein the detecting is by a        Doppler ultrasound device, a Doppler probe device, an        oscillotonometry device, an electroencephalography device, a        transcranial Doppler device, or a cerebral oximetry device.    -   Clause 12. The method of clause 6, wherein the first vascular        location is a heart valve, an aorta, a calf vein, a femoral        vein, a popliteal vein, an iliofemoral vein, an iliac vein, an        inferior vena cava, or a peripheral vein of the patient.    -   Clause 13. The method of clause 6, wherein the second vascular        location is a carotid artery or a vertebral artery of the        patient.    -   Clause 14. A device for diverting emboli from cerebral        circulation of a patient, comprising:        -   a first carotid compression member configured to be aligned            with a first carotid artery of the patient radially between            the first carotid compression member and a cervical spine of            the patient when the device is positioned at least partially            around a neck of a patient, the first carotid compression            member having an unactuated state and an actuated state in            which at least a portion of the first carotid compression            member (i) is closer to the first carotid artery than while            in the unactuated state and (ii) compresses and limits blood            flow through the first carotid artery;        -   a first vertebral compression member configured to be            aligned with a first vertebral artery of the patient            radially between the first vertebral compression member and            the cervical spine when the device is positioned at least            partially around the neck, the first vertebral compression            member having an unactuated state and an actuated state in            which at least a portion of the first vertebral compression            member (i) is closer to the first vertebral artery than            while in the unactuated state and (ii) compresses and limits            blood flow through the first vertebral artery.    -   Clause 15. The device of clause 14, wherein an internal volume        of the first carotid compression member and an internal volume        of the first vertebral compression member are in fluid        communication with each other.    -   Clause 16. The device of clause 14, wherein first carotid        compression member has a maximum height, parallel to a central        axis of the device, that is greater than a maximum height of the        first vertebral compression member.    -   Clause 17. The device of clause 14, further comprising:        -   a second carotid compression member configured to be aligned            with a second carotid artery of the patient radially between            the second carotid compression member and the cervical spine            when the device is positioned at least partially around the            neck, the second carotid compression member having an            unactuated state and an actuated state in which at least a            portion of the second carotid compression member (i) is            closer to the second carotid artery than while in the            unactuated state and (ii) compresses and limits blood flow            through the second carotid artery;        -   a second vertebral compression member configured to be            aligned with a second vertebral artery of the patient            radially between the second vertebral compression member and            the cervical spine when the device is positioned at least            partially around the neck, the second vertebral compression            member having an unactuated state and an actuated state in            which at least a portion of the second vertebral compression            member (i) is closer to the second vertebral artery than            while in the unactuated state and (ii) compresses and limits            blood flow through the second vertebral artery.    -   Clause 18. The device of clause 17, wherein an internal volume        of the second carotid compression member and an internal volume        of the second vertebral compression member are in fluid        communication with each other.    -   Clause 19. The device of clause 17, wherein an internal volume        of the first carotid compression member, an internal volume of        the first vertebral compression member, an internal volume of        the second carotid compression member, and an internal volume of        the second vertebral compression member are in fluid        communication with each other.    -   Clause 20. The device of clause 17, wherein second carotid        compression member has a maximum height, parallel to a central        axis of the device, that is greater than a maximum height of the        second vertebral compression member.    -   Clause 21. A method of diverting emboli from cerebral        circulation of a patient, comprising:        -   while a device is positioned around a neck of a patient,            expanding a first carotid compression member of the device            toward a first carotid artery of the patient to compress and            limit blood flow through the first carotid artery;        -   while the device is positioned around the neck, expanding a            first vertebral compression member of the device toward a            first vertebral artery of the patient to compress and limit            blood flow through the first vertebral artery.    -   Clause 22. The method of clause 21, wherein expanding the first        carotid compression member comprises radially advancing a        portion of the first carotid compression member toward a        cervical spine of the patient.    -   Clause 23. The method of clause 21, wherein expanding the first        vertebral compression member comprises radially advancing a        portion of the first vertebral compression member toward a        cervical spine of the patient.    -   Clause 24. The method of clause 21, further comprising:        -   while the device is positioned around the neck, expanding a            second carotid compression member of the device toward a            second carotid artery of the patient to compress and limit            blood flow through the second carotid artery;        -   while the device is positioned around the neck, expanding a            second vertebral compression member of the device toward a            second vertebral artery of the patient to compress and limit            blood flow through the second vertebral artery.    -   Clause 25. The method of clause 24, wherein expanding the second        carotid compression member comprises radially advancing a        portion of the second carotid compression member toward a        cervical spine of the patient.    -   Clause 26. The method of clause 24, wherein expanding the second        vertebral compression member comprises radially advancing a        portion of the second vertebral compression member toward a        cervical spine of the patient.

Additional features and advantages of the subject technology will be setforth in the description below, and in part will be apparent from thedescription, or may be learned by practice of the subject technology.The advantages of the subject technology will be realized and attainedby the structure particularly pointed out in the written description andclaims hereof as well as the appended drawings.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory and areintended to provide further explanation of the subject technology asclaimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide furtherunderstanding of the subject technology and are incorporated in andconstitute a part of this description, illustrate aspects of the subjecttechnology and, together with the specification, serve to explainprinciples of the subject technology.

FIG. 1 is a view of the blood vessel with the blood carrying emboli. Theblood vessel branches into the vessels carrying blood to different areasand organs.

FIG. 2 is a view of the blood vessel, containing emboli, where anexternal compression of its branch, carrying blood to an organ (such asbrain) will divert potential emboli to another vessel.

FIG. 3 is a schematic representation of the method of protection fromvascular emboli with an option of an automated external compression ofan artery carrying blood to an organ.

FIG. 4 represents a mechanism of detection of embolic particles upstreamfrom the organ to be protected with an automated feedback signalingsystem that is able to trigger the process of arterial compression tolimit the entry of emboligenic particles into this organ.

FIGS. 5 and 6 show compression of an artery, triggered by detection ofthe embolic particles in the afferent vessel, with subsequent diversionof emboli into the less important blood vessel.

FIG. 7 shows release of arterial compression once embolic particles arediverted away from the organ to be protected on the basis of thenegative feedback mechanism, triggered by disappearance of embolicparticles in the afferent vascular pathway.

FIG. 8 is a front view of a patient with embolic particles in the heartand ascending thoracic aorta with a potential for propagation into bothcarotid arteries and other vessels with the source of emboli beingdiseased aorta, aortic valve and the heart.

FIG. 9 is a front view of a patient with the release of embolicparticles arising in the heart, aortic valve and aorta, into thesystemic circulation, including both carotid and vertebral arteries, anddescending thoracic aorta.

FIG. 10 shows accentuation of the process of arterial embolizationduring cardiac contraction (systole).

FIG. 11 is a front view of a patient with external compression of bothcarotid and vertebral arteries that leads to temporary interruption ofthe cerebral arterial inflow, protecting the brain from potentialemboli.

FIG. 12 is a front view of a patient with external compression of bothcarotid and vertebral arteries during cardiac contraction.

FIG. 13 is a front view of a patient with external compression ofcarotid and/or vertebral arteries by virtue of an external compressiondevice and mechanism, actuated by certain physiological parameters.

FIG. 14 is a schematic view of the device for carotid and vertebralcompression, depicted on FIG. 13.

FIG. 15 is a cross-sectional view of a neck of a patient and a deviceattached thereto in an unactuated state.

FIG. 16 is a cross-sectional view of a neck of a patient and a deviceattached thereto in an actuated state.

FIG. 17 is a front view of a patient with a compression device inaccordance with another exemplary embodiment, leading to selectivecompression of vertebral arteries.

FIG. 18 is a front view of a patient with a compression device forvertebral arteries in accordance with yet another exemplary embodiment.

FIG. 19 is a schematic view of the device for vertebral compression,similar to the one depicted on FIG. 18, but carrying features of anadditional exemplary embodiment.

FIG. 20 is a cross-sectional view of a neck of a patient and a device ofFIGS. 18 and 19 for selective compression of vertebral arteries attachedthereto in an actuated state with an option of restrictive pad at theexternal surface of the compression member.

FIG. 21A is a front view of a patient with a compression device inaccordance with another exemplary embodiment.

FIG. 21 B is a cross-sectional view of a neck of a patient and a deviceof FIG. 21A attached thereto in an actuated state when both carotid andvertebral arteries are compressed.

FIG. 22 is a front view of a patient with another embodiment of thecompression device, designed for selective compression of carotidarteries.

FIG. 23A is a cross-sectional view of a neck of a patient and a deviceof FIG. 22 attached thereto in an actuated state with selectivecompression of carotid, but not vertebral arteries.

FIG. 23B is a cross-sectional view of the device of FIG. 23A in aunactuated state.

FIG. 23C is a cross-sectional view of the device of FIG. 23A in anactuated state.

FIG. 23D is a schematic view of the device of FIGS. 23A, 23B and 23C

FIG. 24A is a front view of patient with yet another embodiment of theanti-embolic compression device.

FIG. 24B is a cross-sectional view of the device of FIG. 24A in apartially unactuated state.

FIG. 24C is a cross-sectional view of the device of FIG. 24A in a fullyactuated state.

FIG. 24D is a schematic view of the device of FIG. 24A.

FIG. 25 is a block diagram illustrating a system of the subjecttechnology.

FIG. 26 is an exemplary diagram illustrating modules implementingmethods of the subject technology.

DETAILED DESCRIPTION

In the following detailed description, specific details are set forth toprovide an understanding of the subject technology. It will be apparent,however, to one ordinarily skilled in the art that the subjecttechnology may be practiced without some of these specific details. Inother instances, well-known structures and techniques have not beenshown in detail so as not to obscure the subject technology.

The subject technology relates to prevention of emboli and ischemicinjury (such as ischemia and stroke) as a consequence of emboligenicevent and interventions, e.g., on the heart, heart valves, coronaryarteries and aorta. More particularly, the subject technology relates toan external compression method and device that induce temporarynoninvasive external compression of the blood vessels supplying theorgans at risk for embolic damage. The device can be actuated at themoment of emboligenic intervention and may be triggered and deactivatedon demand and automatically on the basis of patient's physiologicalparameters and detection of emboligenic particles.

Reference will now be made in detail to embodiments of the subjecttechnology, one or more examples of which are illustrated in thedrawings. Each example is provided by way of explanation of the subjecttechnology, and not meant as a limitation of the subject technology. Forexample, features illustrated or described as part of one embodiment canbe used with another embodiment to yield still a third embodiment. It isintended that the present subject technology include these and othermodifications and variations.

It is to be understood that the ranges mentioned herein include allranges located within the prescribed range. As such, all rangesmentioned herein include all sub-ranges included in the mentionedranges. For instance, a range from 100-200 also includes ranges from110-150, 170-190, and 153-162. Further, all limits mentioned hereininclude all other limits included in the mentioned limits. For instance,a limit of up to 7 also includes a limit of up to 5, up to 3, and up to4.5.

The subject technology provides for a method of preventing arterialembolization by diverting emboli from the circulation to be protected,such as cerebral circulation, arm circulation, leg circulation or else.

With reference to FIG. 1, a schematic view of a branching vessel such anaortic arch is shown in which emboli 8 are transferred from the moreproximal arterial trunk 1, such an ascending aorta, into more distalbranches 2 and 3, such as carotid 16, vertebral 12, subclavian 13arteries causing ischemic injury to the organ they supply (such asstroke in the case of embolization of cerebral arteries).

FIG. 1 shows a hypothetical blood vessel 1 branching into the bloodvessels 2 and 3. The antegrade flow 5 in the vessel 1 carries blood,containing emboligenic particles 8 to different areas in the human body,including the organ more vulnerable to ischemic injury (such asbrain)—via the blood vessel 3, and less vulnerable (such as softtissues)—via blood vessel 2. As shown on FIG. 1 the emboli 8 enteringvessel 1 will follow the path of branching into the vessels 2 and 3 andwill enter both vessels 2 and 3 proportionally to the magnitude of flowthrough these vessels. The more flow would occur via the blood vessel 2,the more emboli will enter the organ to be protected (such as brain)leading to serious ischemic injury (such as stroke).

FIGS. 2-7 show the disclosed method of diverging emboli 8 from importantstructures such as brain by exerting external pressure 10 on the bloodvessel 3 (such as carotid or vertebral artery) to create an area of thepressure gradient 9 leading to limitation of the blood flow 5 carryingemboli 8 to the compressed blood vessel 3. Such compression will lead toflow reversal 7 diverting emboli 8 into other less important vessel 2.Acceleration of flow via the blood vessel 2 while the blood vessel 3 iscompressed will lead to a Venturi effect providing additional force 7deflecting the emboli 8 from the vessel 3 into the vessel 2. In order toavoid prolonged limitation of flow to the most important area of thehuman body (such as brain) the time of the protective compression of theblood vessel 2 should be brief. This goal is achieved by a disclosedmethod of vascular compression “on demand”, i.e. at the brief periods oftime when the emboligenic particles are released. As shown on FIGS. 3-7the detectors of emboli “A” and/or “E” can be placed over the source ofemboli (such as heart, heart valve, aorta, etc.) or the blood vessels 1and 3, carrying said emboli to the target organ (such as brain). Theappearance of emboli in said areas when detected as echogenic signal oras another physiological parameter(s), reflecting cardiac ejection andsystole (such as EKG, arterial Doppler, pulse oximetry, arterialwaveform etc.) will be recorded by monitor “B” and will actuate thecompression mechanism “C” that would temporarily compress the bloodvessel 3 leading to limitation, interruption and/or reversal of the flowto the organ to be protected. Detection can occur during and besensitive to flight of emboli or other debris in transit within a bloodvessel. The length of compression and its intensity will be recorded bymonitoring system “D” with a capacity of overruling the act ofcompression if its length or intensity exceed the safe limit Thus, apositive and negative feedback mechanisms will be assured with apotential for an automated auto-regulatory function of such a device.

Once the emboli 8 disappear from the inflow vessel 1 and/or deflectedfrom the blood vessel 3 into the blood vessel 2, the detectors “A”and/or “E” will signal such events to the device “B”, that in turn willprovide negative feedback to the device “C” thus interrupting the act ofcompression 10 and restoring circulation via the blood vessel 3 to theorgan to be protected (such as brain). Considering the fact that themajority of embolic events leading to the organ damage and stroke incardiovascular procedures are very short, this method and system appearto be feasible and reliable, thus providing anti-embolic protection atthe moments of surgery when the risk of embolism is maximal, whilerestoring circulation to such organs when the risk of embolism isminimal. The process of vascular compression alternating with vascularrelease can be repeated on multiple occasions throughout the course ofcardiovascular procedure or a cardiac cycle.

The emboli 8 (FIG. 1) may be fragments of atherosclerotic plaque 19(FIGS. 8, 9) of the ascending thoracic aorta that become dislodgedduring surgical or catheter manipulations on the aorta. Also shown inFIGS. 8 and 9 is calcification of the aortic valve 15 and intra-cardiacembolic particles 20 of the heart 11 that can also be the origin ofemboli 17 eventually present in any artery such as the carotid artery 16or vertebral artery 12. The intra-cardiac emboli 20 may include air,gas, thrombi and atherosclerotic materials. Although all of the variousemboli in the heart 11, aorta and aortic valve 15 need not be present inall instances, they are all shown in FIGS. 8 and 9 for sake of example.Trauma to the heart 11, aortic valve 15 and aortic structures duringplacement and removal of items such as an aortic clamps, guidewires,catheters, balloons and electrophysiological instruments, along withmanipulations such coronary artery bypass grafting, aortic and mitralvalve replacement, catheter ablation, endovascular grafting of theaorta, percutaneous implantation of the aortic or mitral valves,endovascular manipulations on the aorta, aortic branches and the heart11 may give rise to the presence of emboli 17 in the carotid arteries16, vertebral arteries 12, and subclavian arteries 13. Critical momentsof the aforementioned procedures (for example during the aortic crossclamp manipulation, aortic valvuloplasty or valve implantation, coronaryinterventions, and endovascular procedures on the aorta) may causeemboli 17 to form and cause stroke and are referred to as emboligenicevents.

The method and system described can be also applied for prevention ofvenous and pulmonary artery emboli. In this case the detection of themoving venous thrombus/embolus traveling from the peripheral vein towardthe heart and pulmonary artery may initiate the measures for preventionof embolism by virtue of compression of the veins on its path, andsignaling and initiating of other measures of prophylaxis of pulmonaryembolism if necessary (such as deployment of the embolic trap orstarting thrombolytic therapy).

A device similar to the embodiments depicted in FIGS. 13-24 may beplaced around the part of the body containing the target vessel that isnoninvasive and can include a vascular compression member(s) 27 and/or27-V applied to the area of the artery at the certain angle (rangingfrom 0 to 90) to the axis of the artery. The device may comprise atransverse vascular compression member 32. The members 27, 27-V and 32can be converted from an unactuated state to an actuated state in whichthe members 27, 27-V and 32 create an area of compression 23 and 23-V atthe target arteries such as carotid (16), vertebral (12), subclavian(13) or femoral or any other hypothetical vessel 2 to limit blood flowtherethrough into the circulation to be protected such as cerebral orany other circulation. Emboli 8, 17, 18, 20 that are formed in thepatient secondary to emboligenic intervention are diverted into adescending aorta 14 and other less important vascular structures.

As shown in FIG. 9 the emboligenic particles 18 and 20, formed in theheart 11, aortic valve 15 and aorta may enter the carotid arteries 16and vertebral arteries 12, thus becoming cerebral emboli 17 leading toobstruction of cerebral circulation and stroke. As shown on FIG. 10, thedegree of embolization may significantly increase at the time of cardiaccontraction (systole) when intra-cardiac (20) and aortic (18) particlesare forcefully ejected into the systemic circulation, leading to amassive entry of emboli 17 into the carotid 16 and vertebral 13arteries. With respect to our method of anti-embolic protectiondisclosed above it seems to be feasible to protect cerebral circulationby applying temporary pressure on the carotid and, if needed, vertebralarteries for the brief period of time when the risk of embolization ismaximal (FIG. 11). Using detectors of potential emboligenic particlesand emboli in the heart (by ECHO), aorta and its branches (as assessedby Doppler ultrasound) with timely signaling and immediate initiation ofthe protective compression of the target blood vessels such as carotidarteries 16 and/or vertebral arteries 12 will lead to temporarylimitation of the blood inflow such as carotid and/or vertebral flow,thus protecting the organ, such as brain, from embolic load. Uponcreation of the areas of vascular compression 23 (carotid) and 23-V(vertebral), a relative pressure gradient and a “no-flow” or “low-flow”condition is produced in the proximal segments of the compressedarteries such as carotid 16 and vertebral 12 arteries that preventsemboli 18 from entering the circulation to be protected such as cerebralcirculation. The proximal carotid 16 and vertebral 12 arteries are areasof said arteries upstream from the areas of compression 23 and 23-V thathave interrupted or diminished blood flow due to the compression.Potential cerebral vascular emboli such as emboli 18 are diverted intothe more distal vessels such as descending aorta 14 and are illustratedas emboli 21. The thin arrow at the level of aortic arch on FIG. 11shows preferential direction of the blood flow that carries potentialemboli such as cerebral emboli 17 into the descending aorta 14 when theareas of compression 23 and 23-V are created. To protect the brain froman augmented embolic load at the time of cardiac systole (FIGS. 12 and13) we disclose a method of carotid 16 and/or vertebral 12 compressionsynchronized with systolic phase of cardiac activity. The compressionsystem 49 (box C on FIG. 7) is actuated and deactuated by the device 58(Box B) depending on the phase of cardiac activity. Thus, the timing ofthe vascular compression 23 and 23-V in order to limit the inflow ofemboli 17 can be triggered by electrophysiological, hemodynamic and/orpulse-oximetric indices of cardiac contraction, received and processedby the detector 58. On the other hand, the deactuation of thecompression in order to restore arterial perfusion to the brain may betriggered by the same indices, but in the phase of cardiac relaxation.

FIGS. 13-16 disclose an exemplary embodiment that can selectively limitflow to either carotid 16 or vertebral arteries 12, or if necessary,limit flow to all or any combination of these vessels. Said device canbe used to create the areas of compression 23 and 23-V as previouslydescribed to deflect emboli 18 and 20 from the target arteries such ascarotid arteries 16 and vertebral arteries 13. The goal of thiscompression is to prevent the entry of emboli in the circulation to beprotected such as cerebral circulation. The device can be positioned onthe neck of the patient so that a pair of straps 33 and 43 extend aroundthe neck 38 of the patient and are secured to one another via hooks 44and loops 45 that form a hook and loop type arrangement. However, it isto be understood that other mechanisms of securing the straps 33 and 43to one another are possible and that the disclosed arrangement is onlyone exemplary embodiment. Securement of the hooks 44 and loops 45 causesthe device 26 to be retained onto the body part such as the neck 38 ofthe patient. This retention may be loose so that the device 26 has someroom to give on the body part such as the neck 38, or the retention maybe of a tightness that firmly secures the device into the body part suchas the neck 38 and prevents same from moving or twisting. Thecompression device may be a neck collar 26, combination of compressionelements, bars, levers, pads, inserts and screws to provide compressionof the target vessel in accordance with various exemplary embodiments.In other arrangements the compression device 26 may be a strap that layson the front of the body part to be protected such as the neck 38 of thepatient, or may be made of multiple components that are not directlyattached to one another but are positioned proximate to the neck 38 ofthe patient. The device 26 may include two semi-oval halves that may bepositioned around body part of the patient such as the neck 38 orextremity of the patient in accordance with one exemplary embodiment.The device 26 need not be circular in shape. Even if the device 26 isnot circular in shape it may still have a central axis 56 (FIG. 23A) asthe central axis 56 can be located at the center of the vessel and thebody part to be protected such as a carotid artery and the neck 38 ofthe patient and thus may still be a central axis 56 of the device 26.

With reference in particular to FIGS. 23B, 23C and 23D, a pair ofinsertion pockets 41 and 42 are present on the device 26 and may besealed at their tops and bottoms with respect to the vertical direction55. As used herein, the vertical direction 55 may be the direction ofthe device 26 that is parallel to the direction of extension of thecentral axis 56. Strap 33 may extend from the first insertion pocket 41,and strap may extend from the second insertion pocket 42. The firstinsertion pocket 41 forms a cavity into which a first vascularcompression member 27 is located. Member 27 is shown in a relaxed orunactuated state in FIG. 23 and may be made of a flexible material thatcan be stretched or otherwise deformed. The material making up member 27can be nonporous such that member 27 is capable of being filled with gasor liquid that enables the member 27 to expand and at the same time holdthe gas or liquid therein. The pocket 41 may be made of a material thatis different than the material making up member 27.

The second insertion pocket 42 forms a cavity into which the secondvascular compression member 46 is retained. Member 46 may be configuredin a manner similar to member 27 and a repeat of this information is notnecessary. Member 46 may be completely sealed or connected to an openingthat leads into connecting tube 54. Member 46 is in an unactuated statein FIG. 23B. Similarly, for compression of vertebral arteries 13 twoinsertion pockets 41-V and 42-V may be created. Said pockets may containcompression members 27-V and 46-V and other components to facilitatearterial compression as described in previous paragraphs. If necessary,only vertebral compression members can be actuated (FIG. 17). Thespecific anatomic location of the vertebral compression members isdisclosed and should correspond to the level of the C5-C7 vertebra inorder to assure adequate compression of the vertebral arteries 13against the body of C-7 (FIGS. 16 and 20). In other embodiments,however, only the carotid (FIGS. 22 and 23A) or, conversely, onlyvertebral (FIGS. 18-20) compression members could be present. Otherarrangements and combinations of compression members are possible inorder to achieve selective compression of any combination of the carotidand vertebral arteries. Some of these embodiments are shown on FIGS.17-23.

A pressure or compression source 49 is included and is placed intocommunication with the first vascular compression member 27 by the wayof tubing 29 that extends through a port of member 27. A manometer 30may be included in the device 26 at some point between the member 27 andthe pressure/compression source 49 in order to monitor and measurepressure in the system. A detector of emboli and/or EKG, pulse oxymeter,arterial waveform monitor 58 can be bundled with the pressure source 49to assure an option of initiation of the vascular compression once thepotential emboli are ejected or anticipated. FIGS. 23C and 23Dillustrate the device 26 once the pressure/compression source 49 isactivated in order to cause the device 26 to be pressurized. Thepressure source 49 may be a pump that injects air, gas or liquid, suchas water, through the pressure tubing 29. Injection of air or otherwiseincreasing the pressure causes the first vascular compression member 27to expand. Due to fluid communication through the connecting tube 54,the second vascular compression member 46 will likewise expand and thetwo members 27 and 46 may expand at the same rate to the same size.Expansion may be in the radial direction 57 such that the expandablemembers 27 and 46 expand towards the central axis 56 and away from thecentral axis 56. In some exemplary embodiments, the members 27 and 46may expand in the radial direction 57 towards the central axis 56 butnot in the radial direction 57 away from the central axis 56. Thisarrangement may be accomplished by making portions of the compressionmembers 27 and 46, for example the portions facing away from the centralaxis 56 in the radial direction 57, such that they cannot expand whilethe portion facing towards the central axis 56 are in fact expandable.Said arrangements can be also applied to the vertebral compressionelements 41-V, 42-V, 46-V and 27-V and their repetition of them is notnecessary.

The compression members 27 and 46 as well as 27-V and 46-V may beinflated to a pressure level that is just above the level of thepatient's arterial pressure to achieve temporary limitation orinterruption of the arterial blood flow. The arteries to be protectedsuch as both the left and right carotid arteries 16, left and rightvertebral arteries 12, and if needed, femoral and brachial arteries canbe compressed at the same time or separately and in any combination.

Additionally or alternatively, the insertion pockets 41, 42 and 41-V,42-V could have portions that are made of different materials so thatthe parts facing the central axis 56 in the radial direction 57 areexpandable while the parts facing away from the central axis 56 in theradial direction 57 are not expandable. The compression members 27, 27-Vand 46, 46-V are elongated in the vertical direction 55, which is thesame direction as the central axis 56. However, it may be the case thatupon expansion of the expandable members 27, 27-V and 46, 46-V from theunactuated to the actuated states the expandable members 27, 27-V and46, 46-V do not expand in the vertical direction 55. Moreover thecompression members may not be expandable at all and may exertcompression into the underlying vascular structure by virtue oftightening of their attachment apparatus or external straps.

The exemplary embodiment of the device 26 in FIGS. 23A-23D does notinclude a transverse vascular compression member 32 but instead includesonly two compression members 46 that can be expandable. The device 26may be placed onto the patient so that the first longitudinalcompression member 27 overlays the artery to be protected such as acarotid artery 16, or both carotid and vertebral artery 12 (FIGS. 21Aand 21B) such that the artery is located between the central axis 56 andthe member 27 in the radial direction 57. However, other arteries suchas subclavian, or femoral and brachial artery can be compressed in asimilar manner. If needed second vascular compression member 46 and 46-Vmay be laid on top of the other artery such as carotid artery 16 andvertebral artery 12, such that the second artery is likewise between themember 46 and 46-V and the central axis 56 in the radial direction 57.Expansion forces of the expandable members 27 and 46 and 27-V, 46-V orthe outer compression forces on non-expandable or partially expandablemembers 27, 27-V and 46, 46-V may be imparted onto the target arteriessuch as carotid arteries 16 and vertebral arteries 12 so that they arecompressed thus forming the areas of compression 23 and 23-V aspreviously discussed. The pressure at the compression members 27, 27-Vand 46, 46-V may be set so as to exceed the patient's systemic pressureto achieve adequate compression of the carotid arteries 16 and vertebralarteries 12 to have a transient “no-flow” or “low-flow” effect. In somearrangements the pressure of the members 27, 27-V, 32 and/or 46, 46-Vmay exceed the patient's systemic pressure by 10-20 mm Hg, or up to 30mm Hg and even higher in accordance with certain exemplary embodiments.Once the emboligenic part of the procedure is completed, the pressure inmembers 27 and 46 may be released in order to establish adequatearterial flow, such as carotid, brachial or femoral arterial flow. Therelease of pressure can also be triggered by disappearance of embolicparticles in the heart chambers (as detected by cardiac ECHO), aorta (asdetected by arterial Doppler), carotid and cerebral arteries (asdetected by carotid Doppler ultrasound and transcranial Doppler) and bythe indices of cardiac relaxation (diastole) as reflected by EKG, pulseoximetry, arterial pressure waveform and other indices.

An automated self-regulating compression-relaxation mechanism or systemis thus possible, allowing for real-time monitoring and anti-embolicprotection during cardiovascular interventions. Such mechanism or systemwould include the elements A, B, C, D and E as depicted in FIGS. 1-6with a feature of a fully automated vascular compression-relaxationdepending on the embolic load and the phase of cardiac cycle.

Another exemplary embodiment of the device 26 is illustrated in FIGS.24A-24D. The device 26 in this exemplary embodiment also functions tocompress the carotid arteries 16 to create the areas of compression 23.The device 26 includes a first insertion pocket 41 and a secondinsertion pocket 42 but lacks first and second vascular compressionmembers 27 and 46. Instead a first compression member 52 is locatedwithin the first insertion pocket 41, and a second compression member 53is located within the second insertion pocket 42. The compressionmembers 52 and 53 are not expandable but may be made of a material, suchas foam, that can be compressed and then can subsequently expand backinto its original shape. The compression members 52 and 53 mayalternatively be made of a material that does not exhibit any give uponthe application of forces thereto that would be encountered in aprocedure of the type described herein. The compression members 52 and53 may be elongated in the vertical direction 55 and may have a convexshape that faces the central axis 56. The shape of the compressionmembers 52 and 53 at their surfaces that face away from the central axis56 in the radial direction 57 may be different than those that facetowards the central axis 56.

The device 26 may include a transverse carotid compression section 31that is located outward from the compression members 52 and 53 in theradial direction 57 from the central axis 56. A transverse carotidexpandable member 32 may be held by the section 31 and can have an arclength about the central axis 56 that extends beyond both of thecompression members 52 and 53. The transverse carotid expandable member32 has a height in the vertical direction 55 that is the same as, largeror smaller than the height of the compression members 52 and 53 in thevertical direction 55. The member 32 is made of a material that willhold air, gas or liquid such that it can be expanded upon theapplication of fluid thereto. The member 32 has a single port that is influid communication with the pressure tubing 29. Application of pressureto the member 32 will cause the member 32 to expand as shown for examplein FIGS. 24C and 24D. In other embodiments, the compression members 52and 53 can be removed and not present so that only the expandable member32 is present to compress the carotid arteries 16.

The transverse carotid compression section 31 can be arranged so thatall of it is expandable or so that only a portion of it expands as themember 32 expands. Boundary lines 50 and 51 may demarcate areas of thetransverse carotid compression section 31 that can expand from thosethat cannot expand. For example, the portion of section 31 radiallyoutward from the boundary lines 50 and 51 may not be capable ofexpansion while the portions of section 31 radially inward from boundarylines 50 and 51 are capable of stretching and thus expanding orcontracting. This arrangement may cause expansion only, or primarily, inthe radially inward direction upon expansion of the expandable member32. In other embodiments, the section 31 is made of the same materialand exhibits expansibility such that it generally expands in alldirections equally. The expandable member 32 may be arranged so that itdoes not lengthen in the vertical direction 55 upon expansion, or insome arrangements only minimally expands in the vertical direction 55when actuated.

Placement of the device 26 onto the patient may result in the firstcompression member 52 overlaying the target artery such as carotidartery 16 femoral or brachial artery so that the artery to be compressedis between compression member 52 and the central axis 56 in the radialdirection 57. The second compression member 52 will be arranged so thatit overlays the second carotid artery 16 causing it to be between thesecond compression member 52 and the central axis 56 in the radialdirection 57. The expandable members 27, 32 and 46 may be located at theneck 38, upper chest, shoulder, lower abdomen or an extremity of thepatient such that they are secured to the neck 38 or extremity orotherwise proximate. The compression members 27, 32 and 46 need not bein direct contact with the body part of the patient such as the neck 38,chest, abdomen or extremity but only located near them. Application ofpressure via the pressure source 49 causes the transverse compressionmember 32 that may be expandable to exert pressure in the radialdirection 57. This inward radial pressure causes the compression members52 and 53 to move inwards and be urged against the target vessels suchas carotid arteries 16, femoral, brachial or other compressiblearteries. The positioning and configuration of the members 52 and 53function to impart compressive forces onto the arteries to be compressedsuch as carotid arteries 16, femoral, brachial or other arteries whenthe device 26 is pressurized thus resulting in the creation of the areasof compression 23. The other components of the device 26 may be made asthose previously described and a repeat of this information is notnecessary.

Although described as lacking first and second longitudinal vascularcompression members 27 and 46, an alternative arrangement may be made inwhich these members 27 and 46 are present. In such an arrangement, theexpandable members 27 and 46 may expand in order to press thecompression members 52 and 53 towards the arteries to be compressed suchas carotid arteries 16, femoral, brachial or other compressiblearteries.

Moreover, it can also be arranged for compression of the vertebralarteries 12, or both vertebral 12 and carotid 16 arteries by addingadditional compression members in the same arrangement as describedabove.

An alternative exemplary embodiment of the device 26 would be the one inwhich both a pair of longitudinal vascular compression members 27 and 46are present along with a transverse vascular compression member 32. Apair of compression members 52 and 53 may be missing from thisembodiment, or they may be present in certain arrangements. Thisexemplary embodiment may include additional pressure tube lines 47 and48 that are separate from pressure tubing 29 that actuates thetransverse vascular compression member such as carotid compressionmember 32. Pressure tube lines 47 and 48 provide pressure to the firstand second longitudinal vascular compression members 27 and 46 so thatthese members 27 and 46 can be actuated at different rates, amounts,and/or times than compression member 32. This flexibility providesselective pressure adjustments between the transverse vascularcompression member 32 and longitudinal vascular compression members suchas carotid members 27 and 46. This feature will provide an option todecrease or completely eliminate the degree of circumferentialcompression of the body part such as the neck 38 or extremity whenselective inflation of the longitudinal vascular compression members isadequate. Conversely, if inflation of longitudinal compression memberssuch as carotid members 27 and 46 does not lead to sufficient reductionof the arterial flow, an additional inflation of the transverse vascularcompression member such as carotid member 32 would allow one to achievethe desired effect by combining the effect of pressure created in all ofthe members described.

The preferred method of an arterial compression in this case, forexample—compression of the carotid and vertebral arteries, will be aninitial inflation of longitudinal members 27 and 46, followed byinflation of member 32 when necessary. The degree of interruption of thearterial flow in this and other embodiments can be checked by the dataof arterial Doppler, distal pulsation and oximetry as wells as othertechniques of assessment of distal perfusion. The other components ofthe device 26 are the same as those previously disclosed with respect toother embodiments and a repeat of this information is not necessary.

An alternative exemplary embodiment of the device 26 that is beingdisclosed is similar to that previously disclosed with respect to FIGS.23 and 24 and a repeat of the features and functionality that aresimilar between the two need not be repeated. The pressurization of themembers 27, 32 and 46 are different in that the second pressure tube 47feeds into the first longitudinal vascular compression member 27, and inthat the third pressure tube 48 supplies the second longitudinalvascular compression member 46 to allow the members 27 and 46 to bepressurized independently from one another. In this regard, one canapply more or less pressure to member 27 than member 46 so thatcompression of the arteries, such as carotid arteries 16 or femoral andbrachial arteries can be more precisely controlled. The transversevascular compression member 32 is supplied by pressure tubing 29 and isindependent from the expansion of members 27 and 46 such that it can bepressurized to a greater or lesser extent than members 27 and 46. Themanometer 30 may be capable of measuring pressures in all of the lines29, 47 and 48 so that their individual pressures can be monitored. Inuse, one may adjust the pressures in members 27 and 46 first, thensubsequently if needed one may apply pressure into member 32 to causeits actuation so that adequate compression of the carotid arteries 16 isrealized.

The ports for the pressure lines 47 and 48 may be located at the bottomof the expandable members 27 and 46 in the vertical direction 55.However, the ports for pressure lines 47 and 48 need not be in thedisclosed locations in accordance with other exemplary embodiments andmay be above the transverse carotid compression section 31 or at thesame location as the section 31 in the vertical direction 55 in otherexemplary embodiments. The insertion pockets 41 and 42 althoughdescribed as being sealed may have an opening into which the expandablemembers 27 and 46 may be removed and into which first and/or secondcompression members 52 and 53 may be inserted so that the device 26 canfunction with the compression members 52 and 53 and transverse carotidexpandable member 32 as previously discussed.

The arrangement of the device 26 in this case includes a pair oflongitudinal vascular compression members 27 and 46 along with atransverse vascular compression member 32. The circumferential distanceabout the central axis 56 may be the circumferential distance about theneck 38 or extremity of the patient when the device 26 is worn by apatient and thus these two terms can be interchangeable when discussingthe arc length of the member 32. In other exemplary embodiments, the arclength of the member 32 may be from 50-65% (180 degrees-234 degrees)about the circumference of the body part of the patient, from 25%-50%(90 degrees-180degrees) about the circumference of the body partpatient, or from 15%-25% (54degrees-90 degrees) about the circumferenceof the body part of the patient. In yet other exemplary embodiments, themember 32 may extend 360 degrees completely about the body part of thepatient.

The longitudinal vascular compression member such as carotid compressionmembers 27 and 46 are closer to the central axis 56 in the radialdirection 57 than the transverse compression member 32 is to the centralaxis 56. Comparison of FIG. 6C and, using a device for compression ofthe carotid arteries as an example, demonstrates that the lengths of themembers 27, 32 and 46 do not increase in the vertical direction 55, orin the arc length direction, upon moving from the unactuated orientationto the actuated orientation or only slightly expand in these directionsupon actuation. The majority of the expansion may be in the radialdirection 57 either towards the central axis 56 or away from the centralaxis 56 or a combination of the two. In other arrangements, however,expansion of the members 27, 32 and 46 may result in equal expansion inall directions. As previously stated, various components of the device26 may be arranged and function in a manner similar to those aspreviously discussed and a repeat of this information is not necessary.

FIGS. 13-22 disclose modifications of the geometry of the vascularcompression members 27 and 46 with respect to the geometry and anatomyof the patient in order to achieve compression of carotid and/orvertebral arteries in any combination.

FIGS. 15, 16, 20, 21B, and 23A demonstrate the method of use and theeffect of inflation of the vascular compression device such as device 26and it's different embodiments resulting in external compression ofcarotid arteries 16 and/or vertebral arteries 12 leading to transientinterruption of carotid and/or vertebral flow. These figures demonstratethe anatomic relationship of the device 26 to carotid arteries 16,vertebral arteries 12 and surrounding structures 34, 35, 36, 37 and 40of the neck 38. The carotid arteries 16 are bordered by neck muscles 36,esophagus 35, trachea 34 and fat tissues 40. These structures provide aprotective cushion, minimizing the risk of the carotid and vertebralartery injury during external compression. In fact, an externalcompression of arteries 16 and 12 in this setting would lead tosignificantly lower risk of injury to carotid intima than intravascularcarotid occlusion with the balloon or umbrella devices used for cerebralprotection in patients undergoing carotid stenting. The longitudinalcarotid (42, 46) and/or vertebral (42-V, 46-V) expandable members arepositioned along the course of both carotid arteries 16 and/or vertebralarteries 12 on the neck 38. Similar considerations are applicable toprotective compression of all other compressible arteries such asfemoral and brachial arteries and the repeat description of identicalprocesses is not necessary.

The exemplary embodiment of the device 26 may be any one of thosepreviously disclosed that lacks a transverse carotid expandable member32. However, it is to be understood that this is just one example andthat other devices 26 that include member 32 can function in a similarmanner to the device 26 disclosed in FIGS. 8A and 8B. As shown in FIGS.15, 16, 20, 21B, and 23 longitudinal vascular compression members areplaced along the course the target arteries such as carotid and/orvertebral artery, or brachial and femoral artery, or any othercombination of compressible vessels. The lumen of the target arteriessuch as carotid or vertebral arteries is compressed between the vascularcompression members anteriorly (outward in the radial direction 57) andthe cervical spine 37 (or brachial and femoral bones in the case of thearteries of the extremities) posteriorly (inward in the radial direction57). Actuation of the members 27 and 46 and/or 27-V, 46-V cause themembers to move radially inward and compress fat tissue 40 that isimmediately adjacent the device 26. I the case of the carotid arterycompression the vascular compression members 27 and 46 are shown movingin the radial direction 57 inward of portions of the trachea 34 and neckmuscles 36 so that portions of the vascular compression members 27 and46 are closer to the central axis 56 in the radial direction 57 thanportions of the trachea 34 and neck muscles 36. Full expansion of thevascular compression members 27 and 46 may result in inward radialmovement so that they are not radially closer to the axis 56 than anyportion of the esophagus 35. However, other embodiments are possible inwhich at least some portion of the vascular compression members 27 and46 are closer to the central axis 56 than a portion of the esophagus 35.Actuation of the compression members 27-V and 46-V achieve similarcompression of the vertebral arteries against the cervical spine, thatwould be most efficient at the level of C5-C7 vertebrae.

The soft tissues such as the fat tissues 40, neck muscles 36, esophagus35 and trachea 34 around carotid arteries 16 provide a smooth cushionassuring adequate protection against carotid trauma. Same considerationswill hold true in the case of compression of the arteries of upper andlower extremities and the repetition of them is not necessary. In thecase of protection of both carotid arteries, the actuation of themembers 27, 46 and/or 27-V, 46-V causes the areas of compression torestrict blood flow through the carotid arteries 16 and/or vertebralarteries 12 which leads to transient limitation or interruption ofcerebral flow. The trachea 34 and esophagus 35 are not closed orrestricted upon actuation of the expandable members 27 and 46 due to theplacement and specific configuration of said expandable members. Thefact that in most cases this maneuver is performed while the patient isintubated and sedated makes the risk of compression of trachea minimal.Performing the same procedure on the ambulatory basis, however, or whilethe patient is not intubated, may prove to be hazardous. However, insome arrangements some degree of restriction of the trachea 34 and/oresophagus 35 may occur and is considered acceptable in the setting ofgeneral anesthesia with endotracheal intubation and mechanicalventilation. It is advisable, however, to obtain Duplex scan in allpatients planned for this procedure to rule out significantatherosclerotic disease of these vessels, especially if carotid arteries16 are compressed. The mere presence of carotid artery disease in thesepatients should be considered a contraindication to carotid compressiondue to increased risk of carotid atherosclerotic plaque injury leadingper se to distal cerebral embolization and stroke i.e. defeating thepurpose of such a procedure.

The divergence of potential distal emboli such as cerebral emboli 17, 18and prevention of ischemic organ injury such as stroke can be achievedby a noninvasive safe method that involves external compression of thevessel, such as carotid, vertebral or some other arteries and veins,carrying said emboli. The method and device 26 disclosed do not requirepuncture of the skin or vessels and do not necessitate the use ofendovascular devices. The device 26 and disclosed method allow for thedivergence of emboli such as carotid and vertebral emboli 17 and 18 ofall sizes, including those microscopic particles that are too small tobe trapped with the known intravascular filters.

Various types of mechanisms capable of compressing the carotid arteries16, vertebral arteries 12 and other vessels can be included in thedevice 26 in addition to or alternatively to those previously discussed.For example, the device 26 can be supplied with different vascularcompression mechanisms, including different forms and shapes oflongitudinal or transverse bladders, cuffs, compression pads or insertswith the same effect of vascular compression to the point of transientlimitation or interruption of blood flow. The fluid provided topressurize the expandable components of the device 26 from the pressuresource 49 may be a liquid substance in some embodiments. Fluid that is aliquid may be used in the device 26 to effect pressurization and moreuniform constriction of the carotid arteries 16 than gas or air fluidbecause liquid is more non-compressible at the operating range ofpressures. Liquid fluid in the members 27, 32 and 46 may more directlytransmit pressure to the carotid area than gas or air fluid.

Further, although shown as employing a single pressure source 49, it isto be understood that multiple pressure sources of different types maybe used. For instance, the transverse carotid expandable member 32 maybe pressurized by a first pressure source 49 such as a pump, tighteningor direct compressing mechanism while a second source of pressure ofsimilar types is included in the device 26 to provide pressure to thetwo longitudinal vascular compression members 27 and 46.

A monitoring system 58 may be included with the device 26 to assure asafe, adequate, easily manageable and controllable compression ofcarotid, vertebral and other vessels. The monitoring system 58 maycomprise Doppler ultrasound, Doppler probe, oscillotonometry,electroencephalography, transcranial Doppler, cerebral oximetry and/orother techniques. The device 26 may be actuated to such a degree thatthe one, two or more areas of vascular compression formed completelystop the flow of blood into the distal artery such as carotid artery 22,or to an extent that partial flow of blood passes through the areas ofcompression 23 and into the distal artery such as carotid artery 22.

The device 26 provided is a noninvasive and precise apparatus with anoption of assessing a degree and an effectiveness of an interruption ofthe arterial flow by the optional inclusion of a monitoring system 58.The device 26 assures a uniform and reproducible interruption orlimitation of the arterial flow bilaterally minimizing the risk oftrauma to the artery compressed such as carotid and vertebral artery andsubsequent distal emboli, such as cerebral emboli 17. An alarm system 59can be included in the device 26 that is triggered by excessive orlengthy compression of the target artery, such as carotid arteries 16,brachial or femoral arteries. The alarm system 59 may be a part of themonitoring system 58 or may be a different component that is not part ofthe monitoring system 58. The alarm system 59 may thus measure the timeof compression, and the magnitude of compression. Constant monitoring ofarterial, such as carotid 16, brachial or femoral and systemic arterialand device 26 pressures with pressure in the device 26 exceeding onlyslightly the pressure in the arterial system may be conducted to ensuresafe operation and use of the disclosed device 26. The device 26provides a noninvasive compression apparatus that does not require theinsertion of intravascular devices.

A method for reducing or totally preventing cerebral emboli will now bediscussed. A brief compression of arteries to be protected from emboli,such as carotid arteries 16 and vertebral arteries 12 by way of a device26 may be performed first to assure adequate position of the deviceleading to reduction or interruption of flow or pulse through saidartery as assessed by carotid Doppler, a pressure gauge, percutaneouscerebral oximetry or transcranial Doppler.

Once an adequate position of the device 26 is confirmed, the pressure inthe vascular compression components (27, 32, 46 and/or 27-V, 32-V, 46-V)is released and the apparatus 26 is ready for use. The device 26 isinflated to the pressure exceeding patient's systemic pressure justbefore proceeding with the emboligenic part of the procedure. Adequatecompression of the target arteries such as carotid arteries 16 will leadto divergence of blood and emboli away from the vessels to be protectedand toward more distal less important arteries, thus decreasing the riskof deadly complications, such as stroke.

The pressure in the device 26, and thus to the vascular compressioncomponents 27, 32, 46 and/or 27-V, 32-V, 46-V is released after theemboligenic procedure is completed after a full washout of potentialemboli 20, 18 from the heart 11, thoracic aorta and all other potentialsources. The pressurization of the device 26 and its differentcompartments can be repeated any time and on multiple occasions when theemboligenic intervention is contemplated.

Should the physician or physician's assistant forget to release arterialcompression timely, an alarm would go off and the pressure would bereleased spontaneously to avoid undue interruption of the arterial flow.The alarm and deflation could be overridden by the physician whenclinically indicated. The alarm may be sounded by the alarm system 59,and the deflation may be activated by the pressure source 49 and/or thealarm system 59 and/or the monitoring system 58.

The central axis 56 may be present even when the device 26 is notconfigured with straps 33, 43 to form a generally circular member whenviewed from the top as for example in FIG. 6A. In some embodiments ofthe device 26, a circular member is not formed when viewed from the topby the straps 33, 43. For instance, the straps 33, 43 may be missingsuch that the section 31 is attached to sides of a bed or otherwisesecured so that the device 26 is located at the neck 38 of the patient.In such instances, the central axis 56 is still present. The centralaxis 56 may be located at a location within the neck 38 of the patient,for examples shown with reference to FIGS. 8A and 8B. This location maybe at the spinal column 37 of the patient, or may be at the center ofthe neck 38 of the patient. It is to be understood that variousembodiments of the device 26 exist in which the device 26 does not wrapcompletely around the neck 38 of the patient but instead only wrapsaround a portion of the neck 38 of the patient less than 360 degreesfully about the neck of the patient.

The apparatus and methods discussed herein are not limited to thedetection and compression of any particular vessels or combination ofvessels, but can include any number of different types of vessels. Forexample, in some aspects, vessels can include arteries or veins. In someaspects, the vessels can be suprathoracic vessels (e.g., vessels in theneck or above), intrathoracic vessels (e.g., vessels in the thorax),subthoracic vessels (e.g., vessels in the abdominal area or below),lateral thoracic vessels (e.g., vessels to the sides of the thorax suchas vessels in the shoulder area and beyond), or other types of vesselsand/or branches thereof.

In some aspects, the detection and compression systems disclosed hereincan be applied to superthoracic vessels. The suprathoracic vessels cancomprise at least one of intracranial vessels, cerebral arteries, and/orany branches thereof. For example, the suprathoracic vessels cancomprise at least one of a common carotid artery, an internal carotidartery, an external carotid artery, a middle meningeal artery,superficial temporal arteries, an occipital artery, a lacrimal(ophthalmic) artery, an accessory meningeal artery, an anteriorethmoidal artery, a posterior ethmoidal artery, a maxillary artery, aposterior auricular artery, an ascending pharyngeal artery, a vertebralartery, a left middle meningeal artery, a posterior cerebral artery, asuperior cerebellar artery, a basilar artery, a left internal acoustic(labyrinthine) artery, an anterior inferior cerebellar artery, a leftascending pharyngeal artery, a posterior inferior cerebellar artery, adeep cervical artery, a highest intercostal artery, a costocervicaltrunk, a subclavian artery, a middle cerebral artery, an anteriorcerebral artery, an anterior communicating artery, an ophthalmic artery,a posterior communicating artery, a facial artery, a lingual artery, asuperior laryngeal artery, a superior thyroid artery, an ascendingcervical artery, an inferior thyroid artery, a thyrocervical trunk, aninternal thoracic artery, and/or any branches thereof. The suprathoracicvessels can also comprise at least one of a medial orbitofrontal artery,a recurrent artery (of Heubner), medial and lateral lenticulostriatearteries, a lateral orbitofrontal artery, an ascending frontal(candelabra) artery, an anterior choroidal artery, pontine arteries, aninternal acoustic (labyrinthine) artery, an anterior spinal artery, aposterior spinal artery, a posterior medial choroidal artery, aposterior lateral choroidal artery, and/or branches thereof. Thesuprathoracic vessels can also comprise at least one of perforatingarteries, a hypothalamic artery, lenticulostriate arteries, a superiorhypophyseal artery, an inferior hypophyseal artery, an anteriorthalamostriate artery, a posterior thalamostriate artery, and/orbranches thereof. The suprathoracic vessels can also comprise at leastone of a precentral (pre-Rolandic) and central (Rolandic) arteries,anterior and posterior parietal arteries, an angular artery, temporalarteries (anterior, middle and posterior), a paracentral artery, apericallosal artery, a callosomarginal artery, a frontopolar artery, aprecuneal artery, a parietooccipital artery, a calcarine artery, aninferior vermian artery, and/or branches thereof.

In some aspects, the suprathoracic vessels can also comprise at leastone of diploic veins, an emissary vein, a cerebral vein, a middlemeningeal vein, superficial temporal veins, a frontal diploic vein, ananterior temporal diploic vein, a parietal emissary vein, a posteriortemporal diploic vein, an occipital emissary vein, an occipital diploicvein, a mastoid emissary vein, a superior cerebral vein, efferenthypophyseal veins, infundibulum (pituitary stalk) and long hypophysealportal veins, and/or branches thereof.

The intrathoracic vessels can comprise the aorta or branches thereof.For example, the intrathoracic vessels can comprise at least one of anascending aorta, a descending aorta, an arch of the aorta, and/orbranches thereof. The descending aorta can comprise at least one of athoracic aorta, an abdominal aorta, and/or any branches thereof. Theintrathoracic vessels can also comprise at least one of a subclavianartery, an internal thoracic artery, a pericardiacophrenic artery, aright pulmonary artery, a right coronary artery, a brachiocephalictrunk, a pulmonary trunk, a left pulmonary artery, an anteriorinterventricular artery, and/or branches thereof. The intrathoracicvessels can also comprise at least one of an inferior thyroid artery, athyrocervical trunk, a vertebral artery, a right bronchial artery, asuperior left bronchial artery, an inferior left bronchial artery,aortic esophageal arteries, and/or branches thereof.

In some aspects, the intrathoracic vessels can also comprise at leastone of a right internal jugular vein, a right brachiocephalic vein, asubclavian vein, an internal thoracic vein, a pericardiacophrenic vein,a superior vena cava, a right superior pulmonary vein, a leftbrachiocephalic vein, a left internal jugular vein, a left superiorpulmonary vein, an inferior thyroid vein, an external jugular vein, avertebral vein, a right highest intercostal vein, a 6th rightintercostal vein, an azygos vein, an inferior vena cava, a left highestintercostal vein, an accessory hemiazygos vein, a hemiazygos vein,and/or branches thereof.

In some aspects, the subthoracic vessels can comprise at least one ofrenal arteries, inferior phrenic arteries, a celiac trunk with commonhepatic, left gastric and splenic arteries, superior suprarenalarteries, a middle suprarenal artery, an inferior suprarenal artery, aright renal artery, a subcostal artery, 1st to 4th right lumbararteries, common iliac arteries, an iliolumbar artery, an internal iliacartery, lateral sacral arteries, an external iliac artery, a testicular(ovarian) artery, an ascending branch of deep circumclex iliac artery, asuperficial circumflex iliac artery, an inferior epigastric artery, asuperficial epigastric artery, a femoral artery, a ductus deferens andtesticular artery, a superficial external pudendal artery, a deepexternal pudendal artery, and/or branches thereof. The subthoracicvessels can also comprise at least one of a superior mesenteric artery,a left renal artery, an abdominal aorta, an inferior mesenteric artery,colic arteries, sigmoid arteries, a superior rectal artery, 5th lumbararteries, a middle sacral artery, a superior gluteal artery, umbilicaland superior vesical arteries, an obturator artery, an inferior vesicaland artery to ductus deferens, a middle rectal artery, an internalpudendal artery, an inferior gluteal artery, a cremasteric, pubic(obturator anastomotic) branches of inferior epigastric artery, a leftcolic artery, rectal arteries, and/or branches thereof.

In some aspects, the lateral thoracic vessels can comprise at least oneof humeral arteries, a transverse cervical artery, a suprascapularartery, a dorsal scapular artery, and/or branches thereof. The lateralthoracic vessels can also comprise at least one of an anteriorcircumflex humeral artery, a posterior circumflex humeral artery, asubscapular artery, a circumflex scapular artery, a brachial artery, athoracodorsal artery, a lateral thoracic artery, an inferior thyroidartery, a thyrocervical trunk, a subclavian artery, a superior thoracicartery, a thoracoacromial artery, and/or branches thereof.

In some aspects, vessels can include other portions of the vasculature,such as the heart or chambers of the heart. In some aspects, thedetection and compression systems disclosed herein can be applied to theheart or chambers of the heart, such as the right atrium, the leftatrium, the right ventricle, and/or the left ventricle. For example,detection of emboli can be performed within or near one or more chambersof the heart.

In some aspects, a vessel in which detection is performed is differentfrom a vessel in which compression is performed. For example, detectionis performed in a first vessel and compression is performed in a secondvessel. The second vessel can be downstream of the first vessel.

In some aspects, a vessel in which detection is performed is the same asa vessel in which compression is performed. For example, detection isperformed in a vessel at a first location and compression is performedin the vessel at a second location. The second location can bedownstream of the first location.

FIG. 25 is a block diagram illustrating an exemplary computer system 200with which a system (e.g., monitoring module/system and/or detectionmodule/system) of the subject technology can be implemented. In certainembodiments, the computer system 200 may be implemented using hardwareor a combination of software and hardware, either in a dedicated server,or integrated into another entity, or distributed across multipleentities.

The computer system 200 includes a bus 208 or other communicationmechanism for communicating information, and a processor 202 coupledwith the bus 208 for processing information. By way of example, thecomputer system 200 may be implemented with one or more processors 202.The processor 202 may be a general-purpose microprocessor, amicrocontroller, a Digital Signal Processor (DSP), an ApplicationSpecific Integrated Circuit (ASIC), a Field Programmable Gate Array(FPGA), a Programmable Logic Device (PLD), a controller, a statemachine, gated logic, discrete hardware components, and/or any othersuitable entity that can perform calculations or other manipulations ofinformation.

The computer system 200 can include, in addition to hardware, code thatcreates an execution environment for the computer program in question,e.g., code that constitutes processor firmware, a protocol stack, adatabase management system, an operating system, or a combination of oneor more of them stored in an included memory 204, such as a RandomAccess Memory (RAM), a flash memory, a Read Only Memory (ROM), aProgrammable Read-Only Memory (PROM), an Erasable PROM (EPROM),registers, a hard disk, a removable disk, a CD-ROM, a DVD, and/or anyother suitable storage device, coupled to the bus 208 for storinginformation and instructions to be executed by the processor 202. Theprocessor 202 and the memory 204 can be supplemented by, or incorporatedin, special purpose logic circuitry.

The instructions may be stored in the memory 204 and implemented in oneor more computer program products, i.e., one or more modules of computerprogram instructions encoded on a computer readable medium for executionby, or to control the operation of, the computer system 200, andaccording to any method well known to those of skill in the art,including, but not limited to, computer languages such as data-orientedlanguages (e.g., SQL, dBase), system languages (e.g., C, Objective-C,C++, Assembly), architectural languages (e.g., Java, .NET), and/orapplication languages (e.g., PHP, Ruby, Perl, Python). Instructions mayalso be implemented in computer languages such as array languages,aspect-oriented languages, assembly languages, authoring languages,command line interface languages, compiled languages, concurrentlanguages, curly-bracket languages, dataflow languages, data-structuredlanguages, declarative languages, esoteric languages, extensionlanguages, fourth-generation languages, functional languages,interactive mode languages, interpreted languages, iterative languages,list-based languages, little languages, logic-based languages, machinelanguages, macro languages, metaprogramming languages, multiparadigmlanguages, numerical analysis, non-English-based languages,object-oriented class-based languages, object-oriented prototype-basedlanguages, off-side rule languages, procedural languages, reflectivelanguages, rule-based languages, scripting languages, stack-basedlanguages, synchronous languages, syntax handling languages, visuallanguages, wirth languages, and/or xml-based languages. The memory 204may also be used for storing temporary variable or other intermediateinformation during execution of instructions to be executed by theprocessor 202.

A computer program as discussed herein does not necessarily correspondto a file in a file system. A program can be stored in a portion of afile that holds other programs or data (e.g., one or more scripts storedin a markup language document), in a single file dedicated to theprogram in question, or in multiple coordinated files (e.g., files thatstore one or more modules, subprograms, or portions of code). A computerprogram can be deployed to be executed on one computer or on multiplecomputers that are located at one site or distributed across multiplesites and interconnected by a communication network. The processes andlogic flows described in this specification can be performed by one ormore programmable processors executing one or more computer programs toperform functions by operating on input data and generating output.

The computer system 200 further includes a data storage device 206 suchas a magnetic disk or optical disk, coupled to the bus 208 for storinginformation and instructions. The computer system 200 may be coupled viaan input/output module 210 to various devices (e.g., devices 214 and216). The input/output module 210 can be any input/output module.Exemplary input/output modules 210 include data ports (e.g., USB ports),audio ports, and/or video ports. In some embodiments, the input/outputmodule 210 includes a communications module. Exemplary communicationsmodules include networking interface cards, such as Ethernet cards,modems, and routers. In certain aspects, the input/output module 210 isconfigured to connect to a plurality of devices, such as an input device214 and/or an output device 216. Exemplary input devices 214 include akeyboard and/or a pointing device (e.g., a mouse or a trackball) bywhich a user can provide input to the computer system 200. Other kindsof input devices 214 can be used to provide for interaction with a useras well, such as a tactile input device, visual input device, audioinput device, and/or brain-computer interface device. For example,feedback provided to the user can be any form of sensory feedback (e.g.,visual feedback, auditory feedback, and/or tactile feedback), and inputfrom the user can be received in any form, including acoustic, speech,tactile, and/or brain wave input. Exemplary output devices 216 includedisplay devices, such as a cathode ray tube (CRT) or liquid crystaldisplay (LCD) monitor, for displaying information to the user.

According to certain embodiments, the computer system 200 can operate inresponse to the processor 202 executing one or more sequences of one ormore instructions contained in the memory 204. Such instructions may beread into the memory 204 from another machine-readable medium, such asthe data storage device 206. Execution of the sequences of instructionscontained in the memory 204 causes the processor 202 to perform theprocess steps described herein. One or more processors in amulti-processing arrangement may also be employed to execute thesequences of instructions contained in the memory 204. In someembodiments, hard-wired circuitry may be used in place of or incombination with software instructions to implement various aspects ofthe present disclosure. Thus, aspects of the present disclosure are notlimited to any specific combination of hardware circuitry and software.

Various aspects of the subject matter described in this specificationcan be implemented in a computing system that includes a back endcomponent (e.g., a data server), or that includes a middleware component(e.g., an application server), or that includes a front end component(e.g., a client computer having a graphical user interface and/or a Webbrowser through which a user can interact with an implementation of thesubject matter described in this specification), or any combination ofone or more such back end, middleware, or front end components. Thecomponents of the system 200 can be interconnected by any form or mediumof digital data communication (e.g., a communication network). Examplesof communication networks include a local area network and a wide areanetwork.

The term “machine-readable storage medium” or “computer readable medium”as used herein refers to any medium or media that participates inproviding instructions to the processor 202 for execution. Such a mediummay take many forms, including, but not limited to, non-volatile media,volatile media, and transmission media. Non-volatile media include, forexample, optical or magnetic disks, such as the data storage device 206.Volatile media include dynamic memory, such as the memory 204.Transmission media include coaxial cables, copper wire, and fiberoptics, including the wires that comprise the bus 208. Common forms ofmachine-readable media include, for example, floppy disk, a flexibledisk, hard disk, magnetic tape, any other magnetic medium, a CD-ROM,DVD, any other optical medium, punch cards, paper tape, any otherphysical medium with patterns of holes, a RAM, a PROM, an EPROM, a FLASHEPROM, any other memory chip or cartridge, or any other medium fromwhich a computer can read. The machine-readable storage medium can be amachine-readable storage device, a machine-readable storage substrate, amemory device, a composition of matter effecting a machine-readablepropagated signal, or a combination of one or more of them.

As used herein, a “processor” can include one or more processors, and a“module” can include one or more modules.

In an aspect of the subject technology, a machine-readable medium is acomputer-readable medium encoded or stored with instructions and is acomputing element, which defines structural and functional relationshipsbetween the instructions and the rest of the system, which permit theinstructions' functionality to be realized. Instructions may beexecutable, for example, by a system or by a processor of the system.Instructions can be, for example, a computer program including code. Amachine-readable medium may comprise one or more media.

FIG. 26 illustrates an example of a system 300 for diverting emboliwithin a patient, in accordance with various embodiments of the subjecttechnology. The system 300 is an example of an implementation of asystem for diverting emboli within a patient. The system 300 comprisesmonitoring module 302, compression module 304, and control module 306.Although the system 300 is shown as having these modules, the system 300may have other suitable configurations. The modules of the system 300may be in communication with one another. In some embodiments, themodules may be implemented in software (e.g., subroutines and code). Forexample, the modules may be stored in the memory 204 and/or data storage206, and executed by the processor 202. In some aspects, some or all ofthe modules may be implemented in hardware (e.g., an ApplicationSpecific Integrated Circuit (ASIC), a Field Programmable Gate Array(FPGA), a Programmable Logic Device (PLD), a controller, a statemachine, gated logic, discrete hardware components, or any othersuitable devices) and/or a combination of both. Additional features andfunctions of these modules according to various aspects of the subjecttechnology are further described in the present disclosure.

As used herein, the word “module” refers to logic embodied in hardwareor firmware, or to a collection of software instructions, possiblyhaving entry and exit points, written in a programming language, suchas, for example C++. A software module may be compiled and linked intoan executable program, installed in a dynamic link library, or may bewritten in an interpretive language such as BASIC. It will beappreciated that software modules may be callable from other modules orfrom themselves, and/or may be invoked in response to detected events orinterrupts. Software instructions may be embedded in firmware, such asan EPROM or EEPROM. It will be further appreciated that hardware modulesmay be comprised of connected logic units, such as gates and flip-flops,and/or may be comprised of programmable units, such as programmable gatearrays or processors. The modules described herein are preferablyimplemented as software modules, but may be represented in hardware orfirmware.

It is contemplated that the modules may be integrated into a fewernumber of modules. One module may also be separated into multiplemodules. The described modules may be implemented as hardware, software,firmware or any combination thereof. Additionally, the described modulesmay reside at different locations connected through a wired or wirelessnetwork, or the Internet.

In general, it will be appreciated that the processors can include, byway of example, computers, program logic, or other substrateconfigurations representing data and instructions, which operate asdescribed herein. In other embodiments, the processors can includecontroller circuitry, processor circuitry, processors, general purposesingle-chip or multi-chip microprocessors, digital signal processors,embedded microprocessors, microcontrollers and the like.

Furthermore, it will be appreciated that in one embodiment, the programlogic may advantageously be implemented as one or more components. Thecomponents may advantageously be configured to execute on one or moreprocessors. The components include, but are not limited to, software orhardware components, modules such as software modules, object-orientedsoftware components, class components and task components, processesmethods, functions, attributes, procedures, subroutines, segments ofprogram code, drivers, firmware, microcode, circuitry, data, databases,data structures, tables, arrays, and variables.

A phrase such as “an aspect” does not imply that such aspect isessential to the subject technology or that such aspect applies to allconfigurations of the subject technology. A disclosure relating to anaspect may apply to all configurations, or one or more configurations.An aspect may provide one or more examples of the disclosure. A phrasesuch as “an aspect” may refer to one or more aspects and vice versa. Aphrase such as “an embodiment” does not imply that such embodiment isessential to the subject technology or that such embodiment applies toall configurations of the subject technology. A disclosure relating toan embodiment may apply to all embodiments, or one or more embodiments.An embodiment may provide one or more examples of the disclosure. Aphrase such “an embodiment” may refer to one or more embodiments andvice versa. A phrase such as “a configuration” does not imply that suchconfiguration is essential to the subject technology or that suchconfiguration applies to all configurations of the subject technology. Adisclosure relating to a configuration may apply to all configurations,or one or more configurations. A configuration may provide one or moreexamples of the disclosure. A phrase such as “a configuration” may referto one or more configurations and vice versa.

The foregoing description is provided to enable a person skilled in theart to practice the various configurations described herein. While thesubject technology has been particularly described with reference to thevarious figures and configurations, it should be understood that theseare for illustration purposes only and should not be taken as limitingthe scope of the subject technology.

There may be many other ways to implement the subject technology.Various functions and elements described herein may be partitioneddifferently from those shown without departing from the scope of thesubject technology. Various modifications to these configurations willbe readily apparent to those skilled in the art, and generic principlesdefined herein may be applied to other configurations. Thus, manychanges and modifications may be made to the subject technology, by onehaving ordinary skill in the art, without departing from the scope ofthe subject technology.

It is understood that the specific order or hierarchy of steps in theprocesses disclosed is an illustration of exemplary approaches. Basedupon design preferences, it is understood that the specific order orhierarchy of steps in the processes may be rearranged. Some of the stepsmay be performed simultaneously. The accompanying method claims presentelements of the various steps in a sample order, and are not meant to belimited to the specific order or hierarchy presented.

As used herein, the phrase “at least one of” preceding a series ofitems, with the term “and” or “or” to separate any of the items,modifies the list as a whole, rather than each member of the list (i.e.,each item). The phrase “at least one of” does not require selection ofat least one of each item listed; rather, the phrase allows a meaningthat includes at least one of any one of the items, and/or at least oneof any combination of the items, and/or at least one of each of theitems. By way of example, the phrases “at least one of A, B, and C” or“at least one of A, B, or C” each refer to only A, only B, or only C;any combination of A, B, and C; and/or at least one of each of A, B, andC.

Terms such as “top,” “bottom,” “front,” “rear” and the like as used inthis disclosure should be understood as referring to an arbitrary frameof reference, rather than to the ordinary gravitational frame ofreference. Thus, a top surface, a bottom surface, a front surface, and arear surface may extend upwardly, downwardly, diagonally, orhorizontally in a gravitational frame of reference.

Furthermore, to the extent that the term “include,” “have,” or the likeis used in the description or the claims, such term is intended to beinclusive in a manner similar to the term “comprise” as “comprise” isinterpreted when employed as a transitional word in a claim.

The word “exemplary” is used herein to mean “serving as an example,instance, or illustration.” Any embodiment described herein as“exemplary” is not necessarily to be construed as preferred oradvantageous over other embodiments.

A reference to an element in the singular is not intended to mean “oneand only one” unless specifically stated, but rather “one or more.”Pronouns in the masculine (e.g., his) include the feminine and neutergender (e.g., her and its) and vice versa. The term “some” refers to oneor more. Underlined and/or italicized headings and subheadings are usedfor convenience only, do not limit the subject technology, and are notreferred to in connection with the interpretation of the description ofthe subject technology. All structural and functional equivalents to theelements of the various configurations described throughout thisdisclosure that are known or later come to be known to those of ordinaryskill in the art are expressly incorporated herein by reference andintended to be encompassed by the subject technology. Moreover, nothingdisclosed herein is intended to be dedicated to the public regardless ofwhether such disclosure is explicitly recited in the above description.

While certain aspects and embodiments of the subject technology havebeen described, these have been presented by way of example only, andare not intended to limit the scope of the subject technology. Indeed,the novel methods and systems described herein may be embodied in avariety of other forms without departing from the spirit thereof. Theaccompanying claims and their equivalents are intended to cover suchforms or modifications as would fall within the scope and spirit of thesubject technology.

What is claimed is:
 1. A method for diverting emboli within a patient,comprising: detecting a presence of emboli in a first vascular locationof a patient; when the presence of emboli is detected, actuating acompression member aligned with a second vascular location of thepatient when a collar supporting the compression member is positioned atleast partially around a portion of the patient, from an unactuatedstate to an actuated state in which at least a portion of thecompression member (i) is closer to the second vascular location thanwhile in the unactuated state and (ii) compresses and limits blood flowthrough the second vascular location.
 2. The method of claim 1, whereinthe second vascular location is downstream of the first vascularlocation.
 3. The method of claim 1, further comprising: determiningwhether the detected emboli exceed a threshold amount; wherein thecompression member is actuated when the detected emboli exceed thethreshold amount.
 4. The method of claim 1, further comprising:determining whether the detected emboli do not exceed a thresholdamount; transitioning the compression member to the unactuated statewhen the detected emboli do not exceed the threshold amount.
 5. Themethod of claim 1, further comprising transitioning the compressionmember to the unactuated state after the compression member has beenactuated for a predetermined time limit.
 6. The method of claim 1,wherein the detecting is by a Doppler ultrasound device, a Doppler probedevice, an oscillotonometry device, an electroencephalography device, atranscranial Doppler device, or a cerebral oximetry device.
 7. Themethod of claim 1, wherein the first vascular location is a heart valve,an aorta, a calf vein, a femoral vein, a popliteal vein, an iliofemoralvein, an iliac vein, an inferior vena cava, or a peripheral vein of thepatient.
 8. The method of claim 1, wherein the second vascular locationis a carotid artery or a vertebral artery of the patient.
 9. A method ofdiverting emboli from cerebral circulation of a patient, comprising:while a device is positioned around a neck of a patient, expanding afirst carotid compression member of the device toward a first carotidartery of the patient to compress and limit blood flow through the firstcarotid artery; while the device is positioned around the neck,expanding a first vertebral compression member of the device toward afirst vertebral artery of the patient to compress and limit blood flowthrough the first vertebral artery.
 10. The method of claim 9, whereinexpanding the first carotid compression member comprises radiallyadvancing a portion of the first carotid compression member toward acervical spine of the patient.
 11. The method of claim 9, whereinexpanding the first vertebral compression member comprises radiallyadvancing a portion of the first vertebral compression member toward acervical spine of the patient.
 12. The method of claim 9, furthercomprising: while the device is positioned around the neck, expanding asecond carotid compression member of the device toward a second carotidartery of the patient to compress and limit blood flow through thesecond carotid artery; while the device is positioned around the neck,expanding a second vertebral compression member of the device toward asecond vertebral artery of the patient to compress and limit blood flowthrough the second vertebral artery.
 13. The method of claim 12, whereinexpanding the second carotid compression member comprises radiallyadvancing a portion of the second carotid compression member toward acervical spine of the patient.
 14. The method of claim 12, whereinexpanding the second vertebral compression member comprises radiallyadvancing a portion of the second vertebral compression member toward acervical spine of the patient.